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Occurrence of 1,4-Dioxane in New Hampshire’s Water Resources
Brandon Kernen
[email protected] 271-0660
Why Give a Presentation on 1,4-Dioxane? 1) It may be toxic at very low concentrations in water 2) It is present in groundwater at dozens of sites in NH 3) It has been present in many industrial and domestic
products released to the environment for decades. It is also present in the food supply (not fully assessed).
4) It is very mobile in groundwater and difficult to remove
5) Historic contamination clean-up activities did not look for or remediate 1,4-dioxane
6) Owners of private and public water sources generally do not test for 1,4-dioxane
7) Water sources near waste sites that were closed prior to 2005 could currently and unknowingly be impacted by 1,4-dioxane
Topics to Be Covered 1)Why 1,4-dioxane?? 2)Sources of 1,4-dioxane 3)Regulatory response to 1,4-dioxane 4)1,4-dioxane fate and transport 5)1,4-dioxane at release sites 6)1,4-dioxane and public water systems 7)1,4-dioxane in wastewater 8) Why now????
Health Effects of 1,4-Dioxane
• Probable human carcinogen • Confirmed animal carcinogen • Acute nervous system effects • Chronic effects on liver and
kidney
• No federal EPA drinking water standard (included in the next UCMR)
• Common groundwater pollutant • NH adopted and AGQS of 3 parts per billion in 2005 based on
published data at that time at a 1:1,000,000 cancer risk. • California & Illinois have a health action level of 1 ppb • Other states have standards/guidelines from 3 to 85 ppb
Legal Basis for Establishing AGQS 485-C:6 Ambient Groundwater Quality Standards. –
I. The commissioner shall establish and adopt ambient groundwater quality standards for regulated contaminants which adversely affect human health or the environment. Ambient groundwater standards shall apply to all regulated contaminants which result from human operations or activities, but do not apply to naturally occurring contaminants. Where federal maximum contaminant level or health advisories have been promulgated under the Federal Safe Drinking Water Act or rules relevant to such act, ambient groundwater quality standards shall be equivalent to such standards. Where such standards are based upon cancer risks, the ambient groundwater quality standards shall be equivalent to that exposure which causes a lifetime exposure risk of one cancer in 1,000,000 exposed population. Where no federal maximum contaminant level or health advisory has been issued, the commissioner may adopt ambient groundwater quality standards on a basis which provides for an adequate margin of safety to protect human health and safety.
**Does not include financial or technical feasibility considerations**
Env-Dw 707.02 Adjustments to Monitoring Requirements (b) If sample results indicate the presence of contaminants for which MCLs are not listed in Env-Dw 702 through Env-Dw 706 but which are included in the ambient groundwater quality standards (AGQS) specified in Env-Or 603.03, the PWS shall comply with the AGQS specified in Env-Or 603.03.
Legal Basis for State Public Water System Drinking Water Standards
Sources of 1,4-Dioxane • Stabilizer for chlorinated solvents
(TCA) added 2-8% by volume • Paint strippers • Dyes • De-greasers • Varnishes • Impurity in antifreeze and deicing
fluids (ethylene glycol) • Deodorants, shampoos, & cosmetics
– 23 ppm in Clairol Herbal Essence shampoo
– 12 ppm in Hello Kitty Bubble Bath – 50 ppm in Tide
“Levels of 1,4-dioxane in excess of 85
ppm in children’s shampoos
indicate that continued
monitoring of raw materials and finished products is
warranted” – USFDA 2001
More results at
www.1-4dioxane.com
1,4-Dioxane in Personal Care Products
• Is not an input ingredient • Forms as part of a secondary reaction
– Ethylene oxide is added to make cleaning agents less abrasive
– Forms when the sulfation of alcohol ethers • Not listed on bottle as an ingredient • Manufacturing processes can be modified to reduce levels • Some major corporations have reduced this compound in
their products
See http://www.sasoltechdata.com/MarketingBrochures/14Dioxane.pdf
for more information
Why is NH Looking for 1,4-Dioxane Now? • 2003 EPA directed analysis @ Keefe Superfund site.
– “What is 1,4-dioxane?!?” – Most water systems and waste sites didn’t look for it or
used a method with 50 or 100 μg/L reporting limit. – Max. concentration at site – 606 μg/L
• 2005 established ambient groundwater standard of 3 μg/L (enforceable as Drinking Water Standard).
• 2009 required use of Method 8260B SIM,1-2μg/L, detection limit at haz. waste sites, landfills, junkyards and groundwater discharge sites.
• 2010 – USEPA includes 1,4-Dioxane in CCL3 & UCMR3
• 2010 – USEPA Draft Toxicity review suggests NH AGQS could be 0.35 μg/L
• 2011 – NHDES required reporting limit of 0.3 μg/L
• 2011 - Requested nontransient water systems to voluntarily sample
• 2011 – Developed health message for drinking water with >3 μg/L & 0.35-3 μg/L 1,4-dioxane
• 2011 – NHDES provided additional information to water systems about 1,4-dioxane in New Hampshire
Why is NH Looking for 1,4-Dioxane Now?
1
Modified from http://grac.org/presentations/am10/Mohr_T.pdf
1,4-Dioxane Properties Chemical Property
Cyclic ether
Highly soluble in water (100 mg/ml)
Low Henry’s Law Constant (KH = 4.88x10-6 atm m3 mol-1)
Poor adsorption properties (log Kow = -0.27)
Environmental Effect
Chemically Stable
Groundwater plumes expand rapidly
Will not volatilize
Will not be retarded by aquifer sediments
Frequent 1,4-Dioxane Co-contaminants 2-8% 1,4-dioxane in TCA
Dioxane could be controlling contaminant at TCA sites (3 ppb vs. 200 ppb for a clean-up standard)
TCA breaks down to 1,1-DCA or 1,1-DCE
DCA could be primary contaminant w/o TCA & dioxane be present & controlling
Dioxane plumes expand faster than chlorinated solvent plumes.
1,4-Dioxane
1,1,1 TCA
www.michigan.gov/images/figure_2_49944_7.gif
Presence of 1,4-Dioxane at Contamination Sites in NH
• Present at approx. 70 sites to date • Superfund sites, chlorinated sites and landfills • Superfund Sites - 9 • Chlorinated sites – 20 • Landfills – 31 • Range in conc. 1 – 11,000 μg/L • Mean – 228 μg/L • Median - 14 μg/L • Sites with public water supplies affected – 6 • Private wells impacted by 1,4-dioxane - dozens • Historically, many sites were closed after
remediation without assessing for 1,4-dioxane
Presence of 1,4 Dioxane (cont.)
• Groundwater at landfills – – Peterborough –11,000 μg/L; – Newmarket - 760 μg/L; in 22 of 29 wells – Newport - 240 μg/L; in 6 of 9 wells – Colebrook - 110 μg/L; in 21 of 34 wells – Hopkinton - 14 μg/L; in 3 of 8 wells – Chester - 3 μg/L
Presence of 1,4-Dioxane
• Groundwater at chlorinated sites – – Brown’s septage pits 610 μg/L – Janco 300 μg/L – Keewayden Drive 91 μg/L – Concrete Systems Inc. 23 μg/L – EKCO Area 1 4 μg/L
1,4-Dioxane and Public Water Systems
• Spring 2011 – Requested nontransient systems to voluntarily
sample sources for 1,4-dioxane – Provided new health risk assessment
information – Recommended that analytical methods with a
reporting limit of at least 0.3 μg/L be used
• Approximately 215 sources were sampled
1,4-Dioxane in Public Water Systems
• 4 sources with water sources exceeding 3 μg/L • 7 sources with water sources exceeding 0.35 μg/L
• 10 sources with detectable levels of 1,4-dioxane
1,4-Dioxane
August 2011 Sampling Results
Southwest New Hampshire
Treatment Options for 1,4-Dioxane (for < 3 μg/L)
• GAC on a small scale works but is very expensive (short break through/expensive specialized media)
• Reverse osmosis reduces 1,4-dioxane by approx 75% (2012 NHDES/SecondWind Water Systems Study)
• Air stripping poor due to low Henry’s Law coef. but does work (removals of 5% - 40%)
• AOP appears best process – Ozone/peroxide – Peroxide and UV light
There are no known treatment options
to reduce 1,4-dioxane to less than
0.35 μg/L
http://www.baskow.com/client/rttw2011/Final%20Presentations/Tues%20Aft%20Ballroom%20E%20Mahendra%20pres.pdf
What Can Be Done For Private Wells?
• Bottled water (note: Most bottled water sources are not tested for 1,4-dioxane)
• Point of Use Reverse Osmosis • Additional assessments of point of use
treatment options are needed
1,4-Dioxane in Wastewater
• International research estimated 1,4-dioxane would be present at 1 μg/L in treated wastewater
• NHDES confirmed this estimate by sampling treated effluent from two wastewater treatment plants
• To date, 1,4-dioxane is generally not detected in groundwater downgradient of large septic systems
1,4-Dioxane – Analytical Methods
• Three methods (522, 8260CSIM, 8270SIM) can achieve reporting limits of 0.3 μg/L
• Lab accreditation recently offered – NH DHHS (NH), Katahdin Lab(ME), Phoenix
Environmental (CT), Eastern Analytical (NH), ChemServe Lab (NH), Granite State Lab (NH)
• Separate bottles and preservatives are required • EPA is requiring Method 522 for the next UCMR • Method 522 has the lowest reporting limit • Method 522 requires different preservatives for
chlorinated and non chlorinated systems
NHDES 1,4-Dioxane Split Sample Study
LAB SAMPLE A SAMPLE B SAMPLE C SAMPLE D METHOD 1 0.23 <0.25 <0.20 0.98 EPA 522
2 0.17 J <0.20 0.13 1.15 EPA 522
3 0.174 <0.165 <0.174 1.200 8270C SIM
4 0.22 <0.2 0.2 0.99 8260 SIM
5 <0.3 <0.3 <0.3 0.2 8260 SIM
6 0.28 <0.24 <0.24 1.2 8260 SIM
7 <0.20 <0.20 <0.20 1.1 8260 SIM 8 <0.25 <0.25 <0.25 1 8260 SIM
9 <0.27 <0.27 <0.28 1.01 8270C SIM
10 <0.25 <0.25 <0.25 1.4 8260 SIM
Why did we not look for this sooner??
1) Lack of toxicological data 2) Reliance on standard lab methods to
identify a fixed list of contaminants 3) Lack of knowledge about constituents
that were present in chemicals 4) Improved lab detection capabilities
1,4 Dioxane Summary • Highly mobile, recalcitrant compound • Many potential sources • EPA Group B2 carcinogen • Present at many contaminated waste sites • Could be present at or near closed waste sites • Present in some drinking water sources • Majority of public water systems have not sampled for this
contaminant • May be controlling contaminant at some sites • Recent toxicity assessments and upcoming UCMR
sampling likely will keep contaminant in focus • NHDES will continue to promote data collection and public
outreach
Previous/Existing Emerging Contaminants of Concern Initiatives
• Perchlorate Sampling
• Pharmaceuticals and Personal Care Products Sampling - www.nh.gov/medsafety
• Tracking other emerging contaminants with NEIWPCC Work Group
